This encyclopedia entry surveys the moral and political thought of the English philosopher Thomas Hobbes (1588-1679). Hobbes's vision of the world is strikingly original and still relevant to contemporary politics. His main concern is the problem of social and political order: how human beings can live together in peace and avoid the danger and fear of civil conflict. He poses stark alternatives: we should give our obedience to an unaccountable sovereign (a person or group empowered to decide every social and political issue). Otherwise what awaits us is a “state of nature” that closely resembles civil war – a situation of universal insecurity, where all have reason to fear violent death and where rewarding human cooperation is all but impossible.